Poly methacrylic acid-co-ethylene glycol

Qiang Gao, Dan Luo, Jun Ding, Yu-Qi Feng. (2010). Rapid magnetic solid-phase extraction based on magnetite/silica/poly(methacrylic acid-co-ethylene glycol... 

Most anionic pH-sensitive polymers are based on PAA or its derivatives. These systems usually contain moieties anionically charged at a pH above their pK and can attract positively charged therapeutic agents (Palasis, US6506408 B1 Patent), (Dash and Cudworth li, 1998). Peppas and co-workers prepared HGs of poly(methacrylic acid-g-ethylene glycol) P(MAA-g-EG) loaded with insulin exhibited unique pH-responsive characteristics whereby interpolymer complexes formed in acidic media and dissociated in neutral/basic environments (Serra et al, 2006). Consequently, insulin release from the gel was significantly retarded in acidic media while rapid release occurred under neutral/basic conditions. 

Poly(methacrylic acid-co-glycidyl methacrylate-co-poly(ethylene glycol) monomethyl ether methacrylate) water 2005JON... 

A variety of synthetic and naturally derived materials may be used to form hydrogels [60-63]. Synthetic materials include poly(hydroxyethyl methacrylate) (PHEMA), poly(ethylene oxide) (PEO), poly(ethylene glycol) (PEG), poly(vinyl alcohol) (PVA), poly(acrylic acid) (PAA), poly(methyl methacrylate) (PMMA), poly(acrylamide) (PAAm), poly(poly(propylene furmarate-co-ethylene glycol)) (P(PF-co-EG)), poly(vinylpyrrolidone) (PVP), and poly(A-isopropylacrylamide) (PNlPAAm) and its derivatives. Dendrimers and star polymers are exiting new materials because of their large number of functional groups available in a very small volume. 

If one assumes that all macromolecules are bound to stable complexes at an equimolar ratio of poly(methacrylic acid) and poly(ethylene glycol), the reaction yield must be practically 100%. However, the experimentally determined degree of conversion 6 — (Co - Cx)/Co (where Co is the total concentration of CQOH groups in solution, C, the concentration of COOH groups not associated with PEG) is about 0.7. Such a discrepancy between theoretical and experimental degrees of conversion may be explained if one takes into account the possibility of the following equilibrium in the complex particle on link level ... 

Another special type of blend SMP is poly(acrylic acid-co-methyl methacrylate)/poly(ethylene glycol) (P(AA-co-MMA)/PEG) blends, whiA form hydrogen-bonded complexes [52]. It was found that both the concentration and molecular weight of PEG have a strong effect on the complexation with P(AA-co-MMA) gel. In such a system the minimum molecular weight of PEG required for the complex formation lowers to 1000. 

---